scholarly journals MEASUREMENT OF THE CHARGED-PARTICLE MULTIPLICITY IN pp COLLISIONS AT 102 GeV/c.

1972 ◽  
Author(s):  
J Chapman ◽  
N Green ◽  
C Bromberg
1977 ◽  
Vol 129 (3) ◽  
pp. 365-389 ◽  
Author(s):  
W. Thomé ◽  
K. Eggert ◽  
K. Giboni ◽  
H. Lisken ◽  
P. Darriulat ◽  
...  

Author(s):  
S. Acharya ◽  
◽  
D. Adamová ◽  
A. Adler ◽  
J. Adolfsson ◽  
...  

AbstractThe study of (anti-)deuteron production in pp collisions has proven to be a powerful tool to investigate the formation mechanism of loosely bound states in high-energy hadronic collisions. In this paper the production of $$\text {(anti-)deuterons}$$ (anti-)deuterons is studied as a function of the charged particle multiplicity in inelastic pp collisions at $$\sqrt{s}=13$$ s = 13 TeV using the ALICE experiment. Thanks to the large number of accumulated minimum bias events, it has been possible to measure (anti-)deuteron production in pp collisions up to the same charged particle multiplicity ($${\mathrm {d} N_{ch}/\mathrm {d} \eta } \sim 26$$ d N ch / d η ∼ 26 ) as measured in p–Pb collisions at similar centre-of-mass energies. Within the uncertainties, the deuteron yield in pp collisions resembles the one in p–Pb interactions, suggesting a common formation mechanism behind the production of light nuclei in hadronic interactions. In this context the measurements are compared with the expectations of coalescence and statistical hadronisation models (SHM).


1972 ◽  
Vol 29 (25) ◽  
pp. 1686-1688 ◽  
Author(s):  
J. W. Chapman ◽  
N. Green ◽  
B. P. Roe ◽  
A. A. Seidl ◽  
D. Sinclair ◽  
...  

2018 ◽  
Vol 182 ◽  
pp. 02064 ◽  
Author(s):  
Anisa Khatun ◽  

The increase of hard probe production as a function of the charged particle multiplicity in proton-proton and proton-lead collisions is considered to be an interesting observable for the study of multiple parton interactions. In the present work, the correlation between J/Ψ production and charged particle multiplicity has been reviewed in pp collisions at √s = 7 and 13 TeV and p-Pb collisions at √sNN = 5.02 TeV at mid- and forward rapidities. The J/√ measurement in pp collisions at √s = 13 TeV using events triggered by the ALICE electromagnetic calorimeter at midrapidity is discussed in this report, too. An increment of the relative J/Ψ yields has been observed as a function of the multiplicity. The results have also been compared to theoretical model predictions.


2019 ◽  
Vol 79 (10) ◽  
Author(s):  
S. Acharya ◽  
◽  
D. Adamová ◽  
S. P. Adhya ◽  
A. Adler ◽  
...  

Abstract We present a study of the inclusive charged-particle transverse momentum ($$p_{\mathrm{T}}$$pT) spectra as a function of charged-particle multiplicity density at mid-pseudorapidity, $$\mathrm{d}N_{\mathrm{ch}}/\mathrm{d}\eta $$dNch/dη, in pp collisions at $$\sqrt{s}=5.02$$s=5.02 and 13 TeV covering the kinematic range $$|\eta |<0.8$$|η|<0.8 and $$0.15<p_{\mathrm{T}} <20$$0.15<pT<20 GeV/c. The results are presented for events with at least one charged particle in $$|\eta |<1$$|η|<1 (INEL$$\,>0$$>0). The $$p_\mathrm{T}$$pT spectra are reported for two multiplicity estimators covering different pseudorapidity regions. The $$p_{\mathrm{T}}$$pT spectra normalized to that for INEL$$\,>0$$>0 show little energy dependence. Moreover, the high-$$p_{\mathrm{T}}$$pT yields of charged particles increase faster than the charged-particle multiplicity density. The average $${ p}_{\mathrm{T}}$$pT as a function of multiplicity and transverse spherocity is reported for pp collisions at $$\sqrt{s}=13$$s=13 TeV. For low- (high-) spherocity events, corresponding to jet-like (isotropic) events, the average $$p_\mathrm{T}$$pT is higher (smaller) than that measured in INEL$$\,>0$$>0 pp collisions. Within uncertainties, the functional form of $$\langle p_{\mathrm{T}} \rangle (N_{\mathrm{ch}})$$⟨pT⟩(Nch) is not affected by the spherocity selection. While EPOS LHC gives a good description of many features of data, PYTHIA overestimates the average $$p_{\mathrm{T}}$$pT in jet-like events.


2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Sushanta Tripathy ◽  
Ashish Bisht ◽  
Raghunath Sahoo ◽  
Arvind Khuntia ◽  
Malavika Panikkassery Salvan

Recent observations of QGP-like conditions in high-multiplicity pp collisions from ALICE experiment at the LHC warrant an introspection whether to use pp collisions as a baseline measurement to characterize heavy-ion collisions for the possible formation of a Quark-Gluon Plasma. A double differential study of the particle spectra and thermodynamics of the produced system as a function of charged-particle multiplicity and transverse spherocity in pp collisions would shed light on the underlying event dynamics. Transverse spherocity, one of the event shape observables, allows to separate the events in terms of jetty and isotropic events. We analyse the identified particle transverse momentum ( p T ) spectra as a function of charged-particle multiplicity and transverse spherocity using Tsallis nonextensive statistics and Boltzmann-Gibbs Blast-Wave (BGBW) model in pp collisions at s = 13   TeV using PYTHIA8 event generator. The extracted parameters such as temperature ( T ), radial flow ( β ), and nonextensive parameter ( q ) are shown as a function of charged-particle multiplicity for different spherocity classes. We observe that the isotropic events approach thermal equilibrium while the jetty ones remain far from equilibrium. We argue that, while studying the QGP-like conditions in small systems, one should separate the isotropic events from the spherocity-integrated events, as the production dynamics are different.


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